The present invention relates to grove sprayers, and especially to a grove sprayer vehicle for spraying insecticides and the like onto the foliage in a grove.
In the past, it has been common to provide a wide variety of grove sprayers and typically these are wheeled vehicles which may be motorized to provide their own power or may be articulated for attachment to the back of a motorized vehicle. As the sprayer is pulled through a grove between rows of trees, the sprayer sprays the trees on one or both sides of the row. One common type of grove sprayer uses large blowers for delivering blasts of air to the trees on either side of a row and has a spray nozzle placed in the blast of air for feeding an insecticide, fungicide, nutritional, or other sprayable liquid thereinto. The blast of air further disperses the liquid being fed by the nozzle to coat the trees. Typically, in this type of sprayer, an arc is covered on either side irrespective of the size of the trees, so that both foliage areas as well as areas between trees and under trees are commonly sprayed, thereby using considerable more of an insectide than is necessary for spraying the grove or orchard. In addition, it is typical to spray the same amount of insecticide irrespective of the speed of the vehicle, thereby varying the amount of insecticide applied to the tree in accordance with the speed of the vehicle.
To overcome the problem of the varying speed of the vehicle, some grove sprayers have suggested varying the feed of the insecticide to the spray nozzles in accordance with the speed of the vehicle. This can be accomplished by having the operating mechanism coupled to the drive shaft of the vehicle, or alternatively, a separate sensing wheel has been suggested in U.S. Pat. No. 3,489,351 for a high concentrate sprayer. It has also been suggested to use various speed sensing techniques including a radar ground speed sensory. Other prior U.S. patents of interest include U.S. Pat. Nos. 2,475,449; 2,569,274; 2,706,596; 3,252,656; 3,261,551; 3,361,357; 3,489,351; 3,490,695; 3,504,853; and 3,666,177. The present invention attempts to vary the amount of spray sprayed from each nozzle depending upon the speed of the vehicle, and actuates only those nozzles directed towards spray zones where foliage has been specifically sensed and shuts off those nozzles where foliage has not been sensed, so that large amounts of spray can be saved by not wasting insecticide liquid in spraying areas where no foliage is located or by the spraying of excessive spray when the vehicle slows down.